Safety attachment for electric motors



(No Model.)

0. P. BRUSH.

SAFETY ATTACHMENT FOR ELECTRIC MOTORS. No. 391,114. Patented Oct. 16, 1888.

WITNESSES. 6 M. 3. M

' INVENTOR- d1 47 5 I *Z/ Fj /lflorney.

N. PErERs. Photo-ljlhognphur, Washinglnn. 0. cv

UNITED STATES PATENT CHARLES F. BRUSH, OF CLEVELAND, OHIO.

SAFETY ATTACHMENT FOR ELECTRIC MOTGRE.

SPECIFICATION forming part of Letters Patent No. 391,114, dated Cotooer 16, 1888.

Serial K031155132, (No model) Zb aZZ whom it may concern: I

Be it known that I, CHARLES E. BRUSH, of Oleveland,in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Safety Attach ments for ElectroMagnetic Motors; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to safety attachments for electromagnetic motors, and is preferably applied to the governor of such motor, in which, with excessive speed of the motor, a weight is moved outward by centrifugal force against the action of a retaining-spring, the outward movement of the weight being made to close a switch for short-circuiting or cutting out the motor.

In the accompanying drawing is shown a simple and preferable arrangement or" mech' anism for carrying out my invention.

The figure is a side elevation, a portion of the governor-casing being broken away to show the weight and spring.

A represents the armature-shaft, that may I have any variety of electromotor mechanism attached.

A represents the governorcasing, the rim thereof having a hole, a, for the passage of the centrifugal weight B. The latter is more conveniently made in the form of a bolt, the hole a being countersunk to receive the head B of the bolt in position flush with the casing.

C is the retaining-spring, made to act centrip etally on the weight or bolt, the latter passing through a hole made at the center of the spring, with nuts I) and b for compressing the spring, to give the desired tension to thelatter.

A preferable form of circuit-closer or switch is as follows: D and D are standards or posts set at suitable distance apart in convenient proximity to the casing A, these posts being respectively connected with the positive and negative terminals of the motor in any suitable way. A switch-lever or circuit-closer, (Z, is pivoted at cl to the post D. The lever in its depressed position (shown in dotted lines) extends from one post to the other and short circuits or cuts out the motor. The lever (1 may be tilted to the upright position shown in solid lines, the pivotal joint being such that the lever may be turned back a trifle past the center of gravity, so that when left free the lever will stand erect. In its upright position the lever should come as close as may be to the periphery of the casing A without actual contact with the latter, the lever being made to move in the same plane with the weight B.

The spring having been strained to give the proper tension for holding the weight as against the centrifugal force of the latter up to a given speed of the motor, if such speed is exceeded the weight will move outward, and in so do ing will collide with the lever (Z, a slight touch of the weight moving at its highest speed being sufficient to tilt the lever forward, so that the latter will fall by gravity upon the post D, and thus short-circuit or cut out the motor.

In carrying out my invention the mechanical structure and arrangement of parts may be varied indefinitely-for instance, according to the different variety of governor or electric motor to which the safety attachment may be applied-it not being essential to apply the safety attachment directly to the governor, although it is usually more convenient to do so. Any other wheel, rim, or revolving part connected with the motor and suitable for attaching the weight and spring would answer just as well as the governor-casing; also, the form of switch shown, although preferable, might be changed in a variety of ways, according to circumstances, and still be made to accomplish the purpose, so long as the outward movement of the weight cuts out or short-circuits the motor by its impingement against any suitable switching device when the motorhas reached a predetermined speed.

Vhat I claim is 1. In an electric motor, the combination, with a switch, of a radially-movable pin or weight connected with the governorcasing and adapted to be thrown outward by centrifugal action and engage the switch-lever and close the switch, substantially as set forth.

2. In an electric mot-or,the combination, with a switch arranged in close proximity to the governor-casing, of a radially-movable pin or weight connected with the governor-casing, and a spring for restraining the outward movement of the pin or weight, said pin or weight and switch being relatively arranged, so that should themotor attain an abnormally-high rate of speed the switch will be engaged by the by centrifugal force and engage and close the pin and shifted to its closed position and thereswitch should the motor attain an abnormallyby out the motor out of circuit, substantially high rate of speed, substantially as set forth.

as set forth. In testimony whereof I sign this speeifiea- I5 3. In an electric motor,thecombination,with tion, in the presence of two witnesses, this 13th a switch supported on the frame or stationary day of July, 1887.

portion of the motor, said switch constructed to remain normally open and when closed re- I CHARLES BRUSH quiring a manual adjustment to be reopened,

of a pin or weight connected to a moving portion of the motor and adapted to be actuated \Vitnesses:

CHAS. H. DORER, ALBERT E. LYNCH. 

